I once met Roberto Padovani who is the CTO of Qualcomm. He is an alumni of my university, UMass Amherst, and he had come to give a talk.
We bombarded him with some really far fetched questions in information theory and signal optimization and he was able to give really good answers on the spot.
Here is a video of him:
http://www.youtube.com/watch?v=K-c6W0m_nEk
and his profile:
http://www.qualcomm.com/people/roberto-padovani